Efficacy of Transmucosal Nitroglycerin Spray versus Intravenous Lignocaine for the Attenuation of Hemodynamic Responses to Intubation

Abstract

Background and Aims: Intravenous (IV) lignocaine and sublingual nitroglycerin (NTG) obtund intubation responses. We aimed to compare heart rate (HR) and mean arterial pressure (MAP) changes following direct laryngoscopy and intubation after transmucosal NTG spray versus IV lignocaine. Methods: Sixty participants were randomized equally into two groups. Group A patients received IV lignocaine 1.5 mg/kg, 90 s before intubation. Oropharynx of Group B patients was sprayed with 800 μg of NTG oral spray just before induction. General anesthesia regimen for induction, intubation, and maintenance was similar for all patients. HR and MAP at predefined time points and incidence of intraoperative hypotension were noted. Results: Intergroup analysis showed comparable HR in both the groups till 10 min. There was no significant difference in baseline MAP in both the groups. MAP was significantly higher in Group A till 10 min after intubation. Intragroup analysis of HR in Group A showed no significant difference from baseline after induction, 1, 3, and 5 min after intubation. HR at different time points was comparable with baseline during the study period in Group B. A significant fall in MAP from baseline was noted in Group A except at 1 min after intubation. In Group B, a significant fall in MAP from baseline was noted till 15 min after intubation. The incidence of intraoperative hypotension was significantly higher in Group B compared with Group A (40% vs. 3.3%). Conclusion: Both IV lignocaine and transmucosal NTG spray attenuated hemodynamic responses to intubation. However, considering a significantly lesser fall in MAP, IV lignocaine 1.5 mg/kg can be considered superior to 800 μg of transmucosal NTG spray for safely attenuating hemodynamic response to intubation.